The present disclosure relates to a flanged joint. The flanged joint comprises at least one flat gasket held between the facing flange surfaces of components, such as lines or container parts, which store or guide a pressurized medium.
Such flanged joints are known from the prior art, wherein the flat gasket has the function of sealing the flanged joint as hermetically as possible with respect to the environment. Sealing the flanged joint with little or no leakage of environmentally hazardous media, such as oils, acids or toxic gases, is becoming ever more important in view of increased environmental consciousness and legal regulations, such as the TA 2003 air regulation or the VDI 2440 standard.
Such flanged joints often have a drawback in that, due to the continuous contact with the aggressive and/or high-temperature media guided through the lines or stored in the containers, the flat gaskets decompose or dissolve and have to be replaced after a certain amount of time, which adds to personnel overhead.
The present disclosure, thus, relates to a flanged joint having at least one flat gasket that has an increased service life and is essentially maintenance free.
The present disclosure relates to a flanged joint for a pressure medium. The flanged joint includes a first component and a second component having an interior. Also included is at least one flat gasket held between facing surfaces of the first and second components. An annular groove and a radially opposed working diameter are located between the interior and the at least one flat gasket. At least one lamella ring is held in the annular groove and biased, essentially without a gap, against the working diameter.
The present disclosure thus includes, as noted above, arranging, upstream of the at least one flat gasket in the direction of the pressure difference from the pressure side to the environment side, at least one lamella ring that is held in an annular groove. The at least one lamella ring is biased, essentially without a gap, against a working diameter radially opposing the annular groove. In the context of a lamella ring, the working diameter means the diameter of a surface facing the annular groove which receives the lamella ring and along which surface the pressurized medium would flow due to the pressure difference from the pressure side to the environment side.
The biasing of the lamella ring serves to provide sealing, without a gap, with respect to the working diameter, while a small gap is left toward the bottom of the annular groove. The effect of such a lamella ring is, therefore, the same effect as with gap or labyrinth seals. That is, the lamella ring deflects the flow away from the working diameter toward the bottom of the groove and forms a throttle there due to the small leftover gap, at which leftover gap pressure energy is lost. Due to flow redirection and throttling by the lamella ring, a high pressure level is reduced to a low level and the flow is diminished along the working diameter.
The lamella ring acts as a protective seal for the flat gasket downstream and protects it against wear, in particular against high pressures, high temperatures and aggressive media, such as acids or toxic gases. Such lamella rings are made of a thin steel band or of a different material, are structurally simple and require only a small amount of structural space in both axial and radial directions. This is why they are simple to retrofit in existing flanged joints. They are also heat resistant and break resistant, which is why they are highly suitable for protecting the downstream flat gasket against aggressive and high-temperature media.
By providing the lamella rings according to the present disclosure, the service life of the flat gaskets can be considerably increased. In view of the fact that in industrial plants and in the manufacture of chemical equipment, there is often a great number of flanged joints, maintenance overhead and costs can be substantially reduced by the flanged joint of the present disclosure.
The lamella rings of the present disclosure are held in the annular groove with a small axial play allowing for heat expansion.
According to an illustrative embodiment, a plurality of lamella rings can be axially arranged in the annular groove in series. This illustrative embodiment provides that, in view of the multiple labyrinthine redirection of the flow of the pressurized medium, of the plurality of lamella rings, at least the lamella ring facing the pressure side and the lamella ring facing the environment side are biased against the working diameter, and at least one lamella ring axially arranged between these lamella rings is biased against the bottom of the annular groove. As a consequence, in the manner of a labyrinth seal, the medium will be redirected several times between the individual lamella rings, which causes eddies and frictional losses and therefore uses up pressure energy, which advantageously increases the sealing effect. Generally, lamella rings of the same type are used for the lamella rings arranged in the annular groove.
According to the present disclosure, one or more single-turn lamella rings with an axial abutment opening and made of a steel band extending in a single plane are used, for example. Such single-turn lamella rings can be made at particularly low cost and their biasing against the bottom of the groove or against the working diameter is easily adjustable in advance.
Alternatively, according to the present disclosure, single-turn disk-like lamella rings of a steel band formed in the manner and form of a disk spring, can be inserted in the annular groove. Due to the inclination of the lamella rings, the edges of the steel band can be biased against the groove surfaces of the annular groove in a sealing fashion, which also results in an improved sealing effect. It is advantageous for at least one pair of two disk-like lamella rings opposing each other with respect to their disk-like form, to be used, because in this case there are two such sealing edges.
According to another illustrative embodiment, double-turn lamella rings are used, wherein the ends of the double-turns, in a relaxed state of the double-turn lamella ring, protrude to the inside or to the outside of the circular form provided by the remainder of the double-turn lamella ring, and are in alignment with the circular form in the stressed state of the double-turn lamella ring. The ends protruding inside or outside of the circular form ensure that the double-turns are biased toward the inside and toward the outside in the inserted state. The circular form of the closed double-turn over 360° ensures firm contact with the bottom of the groove or with the working diameter.
The two components joined by the flanged joint have a radially overlapping area, so that one of the components has an axially protruding annular collar engaging a complementary annular recess of the other component, which has its radially inner circumferential surface forming the working diameter. Thus, an annular groove radially open toward the outside can be formed in the axially protruding annular collar of the one component, which receives the lamella ring(s).
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.